Centrifugal gas burner



, y 1956 w. R. SWANSON ETAL 2,756,812

CENTRIFUGAL GAS BURNER Filed-Nov. s, 1952 INVENTOR. WILLIS R. SWANSON 1 BY BERNARD W. J E WE LL T @WMW? CENTRIFUGAL GAS BURNER Application November}, 1952, Serial No. 318,444 2 Claims. (Cl. 158-116) The present invention relates to gas combustion apparatus and has for its principal object the creation of a stable flame by positive intimate mixing of gas and cornbustion supporting air, without the possibility of flashback occurring under any condition. In the present invention all of the combustion supporting air and gas are mixed at the point of combustion, there being no aspirating tube or equivalent into which gas may be drawn back to create a flash-back. The present invention operates safely at any fuel input rate. The burner of the present invention permits the use of modulating controls to cause the output of the burner to vary within wide limits to match variable heating demands.

A further object of the present invention is to provide a compact and stable flame under a wide range of operat ing conditions. The centrifugal burner of the present invention creates intense turbulence in the wake of sharp edges of its vanes for mixing the gas and air. This provides compact flames of high efficiency without the production of dangerous amounts of carbon monoxide.

A further object of the present invention is to utilize the high energy of power mixing apparatus for the gas and air, which makes the burner independent of gas pressure fluctuations, as distinguished from the prior practice of utilizing the limited energy provided by the gas pressure in aspirating burners. The present invention comprises a burner head which may be rotated by the same motor which drives the air or water circulating device in a heating appliance.

A further object of the present invention is to provide a burner having forced draft characteristics, thereby eliminating the necessity for a chimney. The forced draft characteristic of the present invention also permits the use of outside air for supporting combustion, rather than limiting the device to the utilization of room air.

A further object of the present invention is to provide a compact gas burner comprising a centrifugal blower having axially arranged vanes, which burner is sturdy and may be of relatively few, easily fabricated and assembled parts.

The objects and advantages of the present invention will be more readily apparent from an inspection of the accompanying drawings taken in connection with the following specification wherein like numerals refer to like parts throughout, in which a preferred embodiment of the burner itself is illustrated in detail.

Referring to the drawings,

Fig. l is a vertical cross-section through a centrifugal gas burner comprisin the present invention, the view being taken substantially along the line 1-1 of Fig. 2; and

Fig. 2 is a vertical section taken substantially along the line 22 of Fig. l and looking in the direction of the arrows.

The present invention is herein illustrated as comprising a centrifugal gas burner fixed to and driven by a driven shaft 10, which is rotated by any suitable means (not shown), the outer end of the shaft being provided nited States Patent 0 blower vanes.

2,756,812 Patented July 31, 1956 ice with an axially extending passage 11 opening to the outer end of the shaft, and which is intersected by a radially extending, gas inlet opening '12. The shaft is supported in a hollow bearing 13'providing a gas inlet chamber 14 within which the inlet opening 12' is situated, and with which communicates a gas supply tube 15. The burner of the present invention is mounted upon the hollow portion ofthe shaft 10 and comprises a hub 16, an integral end disc 17 and a plurality of radially extending vanes 18 overlying and concentrically surrounding the hub 16. Each of the axially extending, peripheral vanes 18 is reverselycurved with respect to the direction of rotation of the blower burner as seen in Fig. 2, which :is the preferred manner of usage of the burner. However, the burner will operate regardless of the direction of rotation, optimum burner operation being provided if the direction of rotation is such that the blades are reversely curved. The peripheral surface of each of the vanes 18 is quite broad and preferably conforms to the surface of a cylinder coaxial with the shaft 10. Each of the vanes is provided with an axially extending, outwardly open groove 19 which provides elongated gas emission troughs or openings ahead of the sharp, trailing edges 20 of the Combustion supporting air is forced outwardly through the passages 21 between the vanes by virtue of the rotation of the blower. If desired, an induction cone 22, indicated in dash outline in Fig. 1, may be provided to direct combustion supporting air into the interior of the'blower.

The peripheral edge of the disc 17 is provided with a circumferential bead 23 over which may be crimped or rolled the edge portion 24 of a sheet metal cap 25 spaced from the end face of the disc 17 and providing therewith a hollow chamber 26 communicating with the gas passage 11. An axially extending, small orifice 27 is drilled through the bead 23 into the base of the groove 19 of each of the vanes 18. Gas which enters the chamber 26 is forced through the orifices 27 by centrifugal pressure, the speed of rotation determining the amount of pressure, and the amount of gas and the length of the jet of gas issuing from each of the orifices. If the burner is rotating slowly, a little gas will issue through each of the orifices to provide a ring of flame closely adjacent the bead 23. If the burner is rotating more rapidly, the length of the jet along the base of the groove 19 will increase and gas will spill out along an increasing amount of the face of the vane, thereby widening the ring of flame in the axial direction of the burner. Regardless of the speed of rotation and the amount of gas, the flame burns in a tight, compact manner close to the surface of the spinning centrifugal blower wheel. If the speed of rotation is low, the force of the streams of combustion supporting air issuing through the passages 21 will be low and the flame will burn closer to the surface of the burner. If the speed of rotation is high, there will be more tendency for the length of the flame to increase. In either event the sharp edges 20 provide extreme turbulence for mixing the sheet of gas flowing across the end of the vane with the stream of air emerging from the passage 21, thus providing a stable flame having maximum efficiency and lowest carbon monoxide production.

By use of the present invention, the burner can operate on relatively low gas pressures, for example, one inch of gas pressure versus the conventional three-inch gas pressure. Consequently, when other burners fail because of insuflicient gas line pressure the present burner can operate satisfactorily. The flame is noiseless under a wide range of conditions and readily adapts itself to modulating operation, in that modulating controls may easily regulate the speed of rotation ofthe centrifugal blower or otherwise control the burner.

Having illustrated and described a preferred embodiment of *the present invention, it should be apparent to those skilled in the art that the same permits of modification in arrangement and detail. We claim as our invention all such modifications as come within the true spirit and scope of "the following claims.

We claim:

1. A gas burner comprising a centrifugal blower having a plurality of axially extending, peripheral vanes, a centrally apertured disc supporting said vanes, a tubular shaft coaxially afiixed to said disc and communicating with the central aperture thereof, and a cap mounted on said disc and forming therewith a hollow chamber concentric With and communicating with said shaft, a plurality of said vanes each having an axially extending, outwardly open groove in its peripheral surface and said disc having a plurality of passages therethrough, each of said passages connecting the interior of said chamber with one of said grooves at an end thereof.

2. A gas burner comprising a centrifugal blower having a plurality of axially extending vanes, a disc supporting said vanes, a concentric hub supporting said disc, a tubular shaft concentrically afiixed to said hub, and means forming with said disc a hollow chamber communicating with said shaft, each of said vanes having an axially extending, outwardly open groove therein, and said disc having a plurality of passages therethrough each connecting the interior of said chamber with one of said grooves.

Eickworth May 27, 1930 Kinkaid et al June 16, 1931 

